Dynamic voltage and frequency scaling (DVFS) is a technique of improving power and heat managing performance by adjusting voltage and operating frequency according to the operation state of a processor.
Intel's Enhanced Intel Speedstep Technology (EIST) and Enhanced C1 (Halt) State (C1E) are examples of power management technologies. In the C1E technology, a CPU receives a halt command when a system maintains an idle state. When receiving the halt command, the CPU reduces the operating frequency and voltage. When receiving a load again, the CPU restores the original operating frequency and voltage.
Alternatively, EIST depends on a CPU load. When the CPU load is low, the CPU maintains a lower voltage and operating frequency. When the CPU load increases, the voltage and the operating frequency are increased.
Turbo boost is a further-developed technology. With turbo boost, operating frequency is increased above a rated frequency but within a thermal design power (TDP) limit according to the state of a CPU.
In processors that have multiple cores within a single cluster, a high-performance core may exhibit high power consumption, heat generation, and instability. As the number of high-performance cores being used increases, power consumption and heat generation increase greatly.